Selector



Aug. 12, 1941. E. c. SAINT-JACQUES SELECTOR Filed May 16, 1959 INVENTOR.U6ENE Can/1.1.: Sm/vr- JQCQUES.

BY allw W W ATTORNEYS.

Patented Aug. 12, 1941 OFFICE SELECTOR Eugene Camille Saint-Jacques,Paris, France Application May 16, 1939, Serial No. 274,036

' In France May 25, 1938 Claims.

The present invention relates to apparatus intended for the separationand classification of solid particles held in suspension in a gaseousfluid, and more particularly to apparatus of the cyclone type. i. e.comprising a cylindrical body in which a current of fluid under pressurecharged with solid particles is introduced tangentially, the bodybeingconnected at its upper end to suction means creating an upward suctioncurrent and being continued at its lower end by a conical portionprovided with an outlet aperture for dust. In such apparatus the currentof fluid admitted tangentially has a downward whirling movement impartedto it, which causes separation and classification of the solid particlesincreasing more and more as the current moves downwards. .The coarserparticles are flung against the wall of the cylindrical body and slidedown the lower cone to the outlet at the bottom, while the finerparticles remaining in the vicinity of the axis of the cylindrical bodyare flectors, for the purpose of ensuring what may be called a rinsingof the solid particles, that is separating from the coarse or mediumparticles the line particles which might otherwise remain imprisonedbetween the latter. Now it has been found that the whirling movementimpressed on the currents of secondary air so introduced tangentiallyinto the cylindrical body, in combination with the whirling movement ofthe principal descending current, may give rise insome zones to aninsuificient acceleration or too great an acceleration of the solidparticles in suspension in this current and that very sensitiveregulation in certain cases becomes difiicult.

If endeavours are made to overcome this drawback by arranging the inletsfor secondary air in a radial disposition or at a certain angle to thedirection of the principal whirling current, difficulty is involved inobtaining a uniform distribution of the rinsing air over the whole ofthe internal periphery of the cylindrical body.

The invention is directed to an improvement applied to classifiers ofthe kind indicated with the object of obviating the above disadvantageand of ensuring a greater eflicaciousness of the rinsing produced by thecurrent or currents of secondary air.

The improvement according to the invention.

secondary air inlets an annular substantially horizontal deflector whichhas the efiect of accelerating the centrifugal action by confining theair to a fairly narrow channel. In this stage of the rinsing it is thenpossible to extract extremely flne dust because of the acceleration ofthe centrifugal -eflect. The other secondary air' inlet or inlets mayhave no particular device for this purpose or they may have either anannular deflector similar to the above-mentioned de flector, or a deviceadapted to subdivide the current of secondary air and placed oppositethe air inlet under consideration below the conical deflector. Such adevice may be for example a cylinder of perforated sheet metal, a ringof vanes or the like. With the latter devices the second current ofrinsing air is admitted with the maximum of centrifugal effect and cancarry out the extraction of coarser particles than otherwise due to thefact that it traverses the surface of material perpendicularly.

The combination of these two arrangements makes it possible according tothe quantity of air distributed between the rinsing systems operating indifferent manners to obtain maximum sensitiveness of operation and agreater certainty in the grading of the particles.

In the accompanying drawing Figure 1 shows by way of example a form ofconstruction of an improved cyclone dust classifler according to theinvention in axial verticalsection.

Figure 2 is a similar section showing a ring of vanes as referred toabove in association with a secondary air inlet means.

Referring to the drawing 1 is the cylindrical body of the cyclonecomprising a part la of larger diameter in the rinsing zone and a lowerconical extension 2 provided with a discharge aperture 3 for the coarseand medium particles. An inlet duct 4 for the fluid charged with thematerials to be separated and classified is connected tangentially tothe cylindrical body I. In this latter is disposed in a known manner aninverted trlmcated cone 5 of which the base is attached to the wall ofthebody l by a ring of vanes 6 and of which the top is in communicationby a duct 1 with the inlet of a fan (not shown). 8 and 9 denote twoinlets for secondary air connected tangentially to the portion Id of theclassified body; opposite these inlets are disposed in the known mannerconical deflectors I0 and II respectively.

Below the secondary air inlet I there is an consists in disposing belowat least one of the annular horizontal deflector I2 and below the airinlet 8 in contact with the conical deflector l I is disposed a cylinderof perforated sheet metal l3, preferably attached to the conicaldeflector ll. Between the lower end of the perforated cylinder l3 andthe cone 2 below it suflicient space is left to permit the escape of anydust which may have lodged in the space between the cone I I, the wallIa and the cylinder l3 when the apparatus is operated on the closedcircuit principle. The perforated cylinder i3 may be replaced by anyequivalent device, for example by rings of vanes II in Figure 2.

As will be clear from the above explanations, the current of fluid underpressure charged with solid particles descends with whirling motion inthe body l-|a. The centrifugal force drives the coarser particlestowards the periphery, while the rising current of fluid due to upwardsuction traverses the apparatus axially and carries with it the finerparticles which have remained at the inner part of the descendingwhirling current. The secondary air entering by the duct 8 is confinedby the horizontal deflector l2 and the conical deflector III to a fairlynarrow annular channel and on emerging therefrom is rotating in theopposite direction to the descending whirling current on which it actstangentially. The secondary air entering by the duct 8 is distributedover the perforated cylinder [3, which breaks up the rotation andensures a fairly uniform distribution of the air in the form of aplurality of jets directed inwards. The vane arrangement l4 in Fig. 2has a similar effect. These jets traverse the descending whirlingcurrent perpendicularly to the motion of the latter. In this way anefllcacious rinsing of the particles is ensured.

The construction shown may be modified in various ways. Thus, theapparatus may comprise only a single inlet for rinsing air, or it maycomprise more than two. If there is morethan one secondary air inlet,the several inlets may be provided with horizontal annular deflectorsonly or with perforated cylinders only or with rings of vanes only.

It may be necessary to deal in particular with mixtures of pulverulentmaterials in which the very fine or very light particle are in a largeproportion, and it may be desired to extract all these particles in asingle operation without carrying away the coarser or heavier elements.In this case it will be preferable in the above example of constructionto combine'with the secondary air inlet 8 nota perforated cylinder l3,but an annular horizontal deflector disposed below this air inlet, justas the deflector I2 is disposed below the secondary air inlet 8.

If instead of two secondary air inlets there are more than two, such anannular horizontal deflector can be disposed below each of them.

With these arrangements the rotation of the What I claim is:

1. In a cyclone selector for solid particles, a cylindrical body havinga tangential inlet through which a gaseous fluid containing the solidparticles to be classified enters said body, and an upper outletcommunicating with suction means and a lower outlet for discharging thelargest particles, a secondary tangential inlet below said first namedinlet, an inverted frustroconical deflector having its upper and outeredge secured to said body below said first named inlet and above saidsecondary inlet and extending downwardly and inwardly past saidsecondary inlet to direct a blast of material entering therethrough,said deflector having a free lower end forming a central passage for airand material, and an annular horizontal deflector attached to the wallof said body substantially opposite the free end of said.frustro-conical deflector, and disposed to reduce the space between thenarrow end of said frustro-conical deflector and said body whereby toincrease the whirling speed of air entering through said secondary airinlet.

2. In a cyclone selector for solid particles, a cylindrical body havinga tangential inlet through which a gaseous fluid containing the solidparticles to be classified enters said body, and an upper outletcommunicating with suction means and a lower outlet for discharging thelargest particles, a secondary tangential inlet below said first namedinlet, an inverted frustraconical deflector having its upper and outeredge secured to said body below said first named inlet and above saidsecondary inlet and extending downwardly and inwardly past saidsecondary inlet to direct a blast of material entering therethrough,said deflector having a free lower end forming a central passage for airand material,

' and means in association with the narrow end materials in suspensionwill be maintained at. I

' all levels in the apparatus, and at each stage of minimum risk ofcarrying away the heavier or denser particles.

of said frustro-conical deflector for diminishing the whirling speed ofair entering through said secondary inlet, said means comprising aperforated cylinder attached to the said frustroconical deflector.

3. In a cyclone selector for solid particles, a cylindrical body havinga tangential inlet through which a gaseous fluid containing the solidparticles to be classified enters said body, and an upper outletcommunicating with suction means and a lower outlet for discharging thelargest particles, a secondary tangential inlet below said first namedinlet, an inverted frustroconical deflector having its upper and outeredge secured to said body below said first named inlet and above saidsecondary inlet and extending downwardly and inwardly past saidsecondary inlet to direct a blast of material entering therethrough,said deflector having a free lower end forming a central passage for airand material, and means in association with the narrow end of saidfrustro-conical deflector for diminishing the whirling speed of airentering through said secondary inlet, said means comprising a ring ofvanes located between said body and the narrow end of saidfrustro-conical deflector.

4. In a cyclone selector for solid particles, a cylindrical body havinga tangential through which a gaseous fluid containing the solidparticles to be classified enters said body, and an upper outletcommunicating with suction means and a lower outlet for discharging thelargest particles, a secondary tangential inlet below said first namedinlet, an inverted frustroconical deflector having its upper and outeredge secured to said body below said first named inlet inlet 7 and abovesaid secondary inlet and extending downwardly and inwardly past saidsecondary inlet to direct a blast of material entering therethrough,said deflector having a free lower end forming a central passage for airand material, and an annular horizontal deflector attached to the wallof said body substantially opposite the free end of said frustro-conicaldeflector, and disposed to reduce the space between the narrow end ofsaid frustro-conical deflector and said body whereby to increase thewhirling speed of air entering through said secondary air inlet, anothersecondary tangential air inlet located below the first, afrustro-conical deflector opposite said inlet to direct awhirling blastof air entering therethrough, and means in association with the narrowend of said last mentioned frustro-conical deflector for diminishing thewhirling speed of air entering through said last mentioned secondaryinlet, said means comprising a perforated cylinder attached to said lastmentioned frustro-conical deflector.

5. In a cyclone selector for solid particles, a cylindrical body havinga tangential inlet through which a gaseous fluid containing the solidparticles to be classified enters said body, and an upper outletcommunicating with suction means and a lower outlet for discharging thelargest particles, a secondary tangential inlet below said first namedinlet, an inverted frustroconical deflector having its upper and outeredge secured to said body below said first named inlet and above saidsecondary inlet and extending downwardly and inwardly past saidsecondary inlet to direct a blast of material entering therethrough,said deflector having a free lower end forming a central pasage for airand material, and an annular horizontal deflector attached to the wallof said body substantially opposite the free end of said frustro-conicaldeflector, and disposed to reduce the space between the narrow end ofsaid frustro-conical deflector and said body whereby to increase thewhirling speed of air entering through said secondary air inlet, anothersecondary tangential air inlet located below the first, afrustro-conical deflector opposite said inlet to direct a whirling blastof air entering therethrough, and means in association with the narrowend of said last mentioned frustro-conical deflector for diminishing thewhirling speed of air entering through said last mentioned secondaryinlet, said means comprising a ring of vanes located between said bodyand the narrow end of said last mentioned frustro-conical deflector.

EUGENE CAMILLE SAINT-JACQUES.

